In any medical diagnostic system, it is important to utilize the fastest patient throughput possible, for both reducing patient discomfort, and maximizing the utilization of the diagnostic apparatus. This is particularly true in computer tomographic scanning systems. State-of-the-art computer tomography (CT) systems or scanners using electron beam deflection technology provide X-ray scanning rates that are much faster than prior CT scanners, such as those using rotating X-ray sources and detectors. The high speed CT scanners that use electron beam deflection technology removes the scanning speed of the CT apparatus as the limiting factor that reduces patient through-put. To maximize the economy of using the new high speed scanner CT apparatus, it is important to maximize the patient throughput in the associated system.
A number of prior systems have shown the use of multiple patient tables in association with scanning systems. One such system is the General Electric Signa brand MRI System, manufactured by the General Electric Corporation. The system wholly relied upon manual movement of the patient tables, and did not support patient prepositioning.
In Hynes, Jr. U.S. Pat. No. 4,105,923, entitled "PATIENT HANDLING SYSTEM AND APPARATUS FOR TOMOGRAPHIC SCANNING", a manually moveable cart incorporating a longitudinally moveable pallet section is shown. The patient is placed on the pallet on top of the cart, and moved to the CT apparatus. The patient is then wheeled manually on the cart to the CT scanning device, and the cart is positioned over an elevatable island, and secured to the island. The island is then elevated and positioned for permitting the CT scanner to scan a desired portion of the patient's body. The use of one-cart, two-cart, and three-cart systems is discussed. In the one-cart system, all preparation of the patient is performed in the CT scanner room. In the two and three-cart systems, initial preparation of the patient is performed in a room immediately adjacent to the scanner room. In the latter system, preparation and depreparation of the patient is performed in the room adjacent to the scanner room. All movement of the patient on the specially designed carts is manual, and as taught the movement cannot be direct. Also, the carts must be rotated in order to properly align them with the scanning device.
In Carper et al., U.S. Pat. No. 4,727,328, entitled "PATIENT HANDLING ARRANGEMENTS FOR NMR IMAGING SYSTEMS", a manually moveable patient cart is shown. The cart includes a patient pallet that can be locked to the top of the cart. A patient secured to the pallet is manually moved on the cart to the NMR device. The pallet is then unlocked from the cart, and moved longitudinally to position the patient as required within the cylindrical coils of the NMR apparatus. The cart has a vertically extendable platform for adjusting the height of the patient on the pallet, prior to releasing the pallet for pushing it and the patient into the NMR device.
In another known system, known as the Siemens' "Trauma/ICU Stretcher", manufactured by Siemens Corporation, Iselin, NJ, a manually moveable stretcher is supported upon the top of a wheeled cart. With the patient secured to the stretcher, the cart is wheeled adjacent to a patient bed support of a CT scanner apparatus, whereafter the stretcher can then be manually slid from the cart directly onto the patient bed support, and secured to the latter. The bed support is then operated for vertically positioning the patient, whereafter the stretcher is moveable in the horizontal plane for positioning the patient within the scanning region of the associated CT scanner. After the scanning operation is complete, the stretcher with the patient is moved back into position on the bed support. The bed support is then vertically positioned for permitting the stretcher to be slid off of the bed support back onto the cart, for moving the patient out of the scanner room.
The prior patient handling systems do not provide for direct movement or prepositioning of a patient between preparation/depreparation areas and a CT scanner room. As a result, time must be spent in positioning manually movable patient carts, for transferring a patient either to and from the patient bed supports of a scanner device, and/or for positioning the patient relative to the scanner device. Nor do the prior systems provide for automatic movement of a patient between preparation/depreparation rooms, and a CT scanner device within a scanner room.
The present inventor recognized that to reduce patient throughput time or optimize patient handling in a CT scanner system, a patient should be conveyed on a moveable cart in a straight line, with little or no rotation of either the patient or the cart being required, with the patient being prepositioned for scanning prior to entering the scanner room. Also, the present inventor recognized that by minimizing the amount of time a patient must spend within a scanner room, optimal use of the actual CT scanner apparatus for scanning the maximum number of patients possible within a given period of time will be attained.